Furthermore, these cities become, to some extent, disconnected from the nation-state:
These cities constitute a system rather than merely competing with each other. What contributes to growth in the network of global cities may well not contribute to growth as nations.(9)
She describes the architecture of a global network of cities: key cities as nodes, linked in a variety of ways, including financial flows, communication, travel, and trade.
For Sassen, one of the important reasons for the formation of these global cities are changes in the financial system from the 1980s on, requiring the concentration of firms (and the workers at all levels to support the concentration) in the global cities to make the system work.
That is, the emergence of speculative capital carried with it certain imperatives that contribute not just to globalization, but to the network of globalization. The city nodes provide a concrete reflection of the digitalized connections of 21st century finance.